Top Chemical Resistant Plastics: Fluoropolymers Plastics

Fluoropolymers  were first serendipitously discovered in 1938 when Roy Plunkett at DuPont was experimenting with some tetrafluoroethylene gas.  He accidently made PTFE (polytetrafluoroethylene), known commonly as Teflon®.  Since that lucky day, many fluoropolymers have been developed, including PVDF (poly vinylidene difluoride); ETFE (polyethylenetetrafluoroethylene); FEP(fluorinated ethylene propylene); PFA (perfluoroalkoxy); ECTFE (ethylene chlorotrifluoroethylene) and PCTFE (polychlorotrifluFluoropolymers Plasticsoroethylene).

Even non-plastics experts have probably seen Teflon® in action, even if they don’t realize it, as the material is commonly used to coat nonstick cookware.  With high heat resistance, excellent chemical resistance and a very low coefficient of friction this plastic is well suited to that purpose.  (Although Teflon® is an impressive material, I would advise you not to get too crazy with your cookware.  As the author has personally experienced, Teflon® spatulas and cooking spoons will melt if left over open flame.  Say, the open flame of a gas range stovetop.  But that’s a story for another day…)  But there is so much more to the story of fluoropolymers than pots and pans.

Fluoropolymers plasticsalso have a very low coefficient of friction making them naturally very slippery.  Indeed PFA is said to be the only material that a gecko cannot stick to. Because of their low coefficient of friction fluoropolymers are known to be hard to glue.  There is even a fluoropolymer paint designed to cause insects to slide off surfaces.  This slipperiness and non-porousness makes fluoropolymers naturally anti-microbial and a good pick for medical applications.

Additionally, fluoropolymers plastics are hydrophobic in that neither water nor water containing substances can wet them. They also have a flammability rating of UL94 V-0 so they are self-extinguishing.  Fluoropolymers also have excellent dielectric properties, making them great insulators.

Fluoropolymers plastics are also known for continuous service in extreme temperatures.  PFA performs up to 260°C/500°F while FEP can sustain 200°C/393°F.  ETFE has values of 150°C/302°F.   Many fluoropolymers plastics can withstand cryrogenic temperature. PTFE can withstand temperature values of -240°C/-400°F to 260°C/500°F.  ECTFE also has excellent cryogenic properties and performs well between  -76°C/-105°F to 150°C/302°F while PVDF can withstand temperatures of -30°C/-22°F  to 150 °C/302°F.  PCTFE performs well in a temperature range of  -240°C/-400°F to 204°C/400° F°.

The down side of fluoropolymers is that they are not all that strong.  With a tensile strength of 7800 psi/53.8MPa PCTFE is the one of the strongest along with ECTFE with also has a UTI of 7800 psi/53.8MPa.  ETFE comes in next at 7500 psi/51.7MPa.  PVDF has an ultimate tensile strength of 4000-6000 psi/27.6-41.4MPa and PFA has values of 4300psi/24MPa.  The ultimate tensile strength of PTFE is 2,500-4,000psi/17.2-27.6 MPa while FEP is 3,000 psi/20.7 MPa. But

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